Just to ask if anyone is aware of any interesting math podcasts? I am particularly interested in podcasts describing mathematics in the wider world; but interesting academic podcasts would also be useful.

I produced a math podcast "dansmathcast" from 2005-08 that is still up on iTunes, in the Education category, with 33 episodes so far.

It's like a math variety show, with a chapter-of-the-week, mathematics for the masses, math or myth, an advanced topic, and other features, capped off with a math joke. Listen to dansmathcast; in a half hour you'll be smarter!